Update 10pm: Catalan lawmakers have signed a document they are calling a declaration of independence from Spain but are delaying its implementation.
Regional president Carles Puigdemont was the first to sign the Declaration of the Representatives of Catalonia document.
Dozens of other lawmakers signed it after him in the regional parliament in Barcelona.
The signing ceremony came a few hours after Mr Puigdemont addressed the parliament, saying Catalans had earned the right to independence from Spain after a referendum on October 1.
However, he called for dialogue with Spain's government, which has condemned the referendum as illegal and unconstitutional.
The central government in Spain responded by saying it did not accept the declaration of independence by the separatists and did not consider the October 1 referendum or its results to be valid.
Mr Puigdemont said the landslide victory in the referendum gave his government the grounds to implement its long-held desire to break century-old ties with Spain.
However, he proposed the regional parliament "suspend the effects of the independence declaration to commence a dialogue, not only for reducing tension but for reaching an accord on a solution to go forward with the demands of the Catalan people".
"We have to listen to the voices that have asked us to give a chance for dialogue with the Spanish state," Mr Puigdemont said.
Such a move would help reduce political tensions and reach "an accord on a solution to go forward with the demands of the Catalan people", Mr Puigdemont added.
About two dozen tractors flying secessionist flags paraded near parliament and thousands of separatists gathered in the promenade next to Barcelona's Arc de Triomf, where the movement's main grassroots group has called for a rally.
The Spanish government does not accept the "implicit" declaration of independence by the Catalan separatists and the results of a banned referendum cannot be considered valid, an official said.
The official told The Associated Press that the government of Prime Minister Mariano Rajoy cannot accept validating a Catalan referendum law that was suspended by Spain's Constitution and called the referendum "fraudulent and illegal".
Mr Rajoy's government "considers it inadmissible to make an implicit declaration of independence and then leave it in suspension in an explicit manner," according to the official.
Mr Puigdemont was highly critical of the Spanish government's response to the referendum and the violent police reaction that left hundreds injured on voting day, but said Catalans have nothing against Spain or Spaniards, and that they want to understand each other better.
"We are not criminals, we are not crazy, we are not pulling off a coup, we are not out of our minds. We are normal people who want to vote," he said.
Opposition leader Ines Arrimadas of the Ciudadanos (Citizens) party slammed the speech.
"This is a coup. Nobody has recognised the result of the referendum. Nobody in Europe supports what you have just done," she said.
"Stop saying the Catalan people are united. Above all after what you have done. You have forced us to turn against one another," she said, addressing Mr Puigdemont during the parliament session.
"The majority of Catalans feel they are Catalans, Spanish and Europe. We won't let you break our hearts into bits," Ms Arrimadas said.
Some 2.3 million Catalans - or 43% of the electorate in the region - voted in the referendum.
Regional authorities say 90% of those who voted were in favour of independence.
Update 7.45pm: Catalan president Carles Puigdemont has said he has a mandate to declare independence for the north-eastern Spanish region but is prepared to wait "a few weeks" in order to facilitate a dialogue.
An opposition leader described Mr Puigdemont's plans as "a coup" which has no support in Europe.
Mr Puigdemont told the Catalan parliament a landslide victory in the disputed October 1 referendum on independence gives his government grounds to implement its long-held desire to break century-old ties with Spain but he is suggesting holding off.
His speech was highly critical of the Spanish government's response to the referendum but he said Catalans have nothing against Spain or Spaniards, and that they want to understand each other better.
At the end of his speech, Mr Puigdemont was applauded by standing separatist lawmakers.
The opposition leader in Catalonia's parliament said Mr Puigdemont's statement that he has a mandate to declare independence from Spain "is a coup" and has no support in Europe.
Ines Arrimadas of the Ciudadanos (Citizens) party said the majority of Catalans feel they are Catalans, Spanish and European, and that they will not let regional officials "break their hearts".
Update 6.45pm: Catalonia’s regional leader has indicated to the Catalonian parliament that he wants to respect the will of the people who have voted Yes to independence.
In a highly anticipated address that marks a critical point in the standoff between separatists and Spain’s central authorities Mr Puigemont said: "The ballots say Yes to independence this is the will that I want to go forward with.
"At this historical moment as the president of Catalonia, I want to follow people's will for Catalonia to become an independent state."
Mr Puigdemont went on to say, however, that he would suspend effects of declaration of independence for further talks.
"Today I assume the mandate for Catalonia to become an independent state in the form of a republic ... We're suspending the declaration of independence for a few weeks, because we want a reasonable dialogue, a mediation with the Spanish state."
Catalan president says Catalonia has won right to independence, but suspends declaration to pursue dialogue #CatalanReferendum— David Shelton (@davidoshelton) October 10, 2017
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Earlier: Catalonia’s regional leader is addressing the Catalonian parliament in a highly anticipated session that could spell the birth of a new republic, marking a critical point in the standoff between separatists and Spain’s central authorities.
His speech had been delayed for over an hour.
Carles Puidgemont and his advisors have gone into private meetings and it was suggested the delays could be due to ongoing international mediation, problems with his his party's coalition partners or ongoing attempts at a n ational level to have his parliament appearance cancelled
The Spanish government just sent extra security to Catalonia https://t.co/zZ7JekDmxS— angela mcevoy (@maxmcevoy) October 10, 2017
Earlier: Security is tight in Barcelona and police cordoned off a park surrounding the legislative building where Catalan president Carles Puigdemont is expected to walk a fine line when he addresses regional legislators.
The speech will need to appease the most radical separatist-minded supporters of his ruling coalition, but Mr Puigdemont faces shutting down any possibility of negotiating with Spain if he adopts a hard line.
The Catalan leader has not revealed the precise message he will deliver in the address, but separatist legislators and activists have said they will not be satisfied with anything short of an independence declaration.
A full declaration of secession - or an outright proclamation of a new Catalan republic - would meet fierce opposition by central Spanish authorities, who could take the unprecedented step of suspending the self-government of Catalonia and taking over some or all powers in the region.
Mr Puigdemont himself could end up in prison.
Some 2.3 million Catalans - 43% of the electorate in the north-eastern region - voted in the October 1 independence referendum, which the Spanish government said was illegal.
Regional authorities say 90% who voted were in favour and declared the results of the vote valid.
The ballot was marred by violence as riot police tasked with stopping the voting clashed with voters, leaving hundreds injured.
The political deadlock has plunged the country into its deepest political crisis in more than four decades, since democratic rule was restored following the dictatorship of General Francisco Franco.
In the streets of Barcelona, expectations were divided between those who want to see the birth of a new nation and others opposed to the idea. Some feared a drastic backlash from the Spanish central authorities.
The Catalan parliament’s governing board acknowledged on Tuesday morning it had received the results in last week’s disputed independence referendum, but a parliamentary official said the board refrained from putting the results through normal parliamentary procedures to elude any legal problems, because the referendum and its legal framework have been suspended by the national Constitutional Court.
Hundreds of thousands have turned out for street protests in Barcelona and other towns in the past month to back Catalan independence and protest against police violence during the vote. Those committed to national unity have also staged separate, large-scale rallies.
The tension has impacted the economy, with dozens of companies already relocating their corporate address away from the troubled region to remain under Spanish and European laws if Catalonia manages to secede.